The REXROTH R911391203 MSK100B-0200-NN-S1-LP0-NSNN is a high-performance synchronous servo motor from the IndraDyn S MSK family, engineered for demanding industrial motion-control applications that require a combination of torque density, positioning accuracy, repeatability, and mechanical robustness. In the MSK range, the MSK100 frame represents a larger and more powerful platform, intended for machine builders and maintenance teams that need a servo motor capable of handling dynamic motion while maintaining precise closed-loop control. Publicly available series information identifies the MSK100 family as part of the IndraDyn S range for high-speed and high-power applications where precision remains critical.
What makes this specific configuration commercially relevant is the balance between strong torque output and proven industrial durability. The published MSK100B-0200 performance data shows a maximum speed of 4100 rpm, continuous torque at standstill of 28 Nm, peak torque of 102 Nm, and a rotor inertia of 0.0192 kg·m². Those values place the motor in a category suitable for heavy-duty servo axes that must accelerate controlled loads, hold position reliably, and respond predictably during repeated motion cycles. Its listed weight of 34 kg also indicates a solid mechanical structure appropriate for larger machine axes rather than lightweight compact automation modules.
Key Product Data
| Item | Specification |
|---|---|
| Brand | Rexroth |
| Order Number | R911391203 |
| Model | MSK100B-0200-NN-S1-LP0-NSNN |
| Product Family | IndraDyn S MSK |
| Motor Type | Synchronous servo motor |
| Maximum Speed | 4100 rpm |
| Continuous Torque at Standstill | 28 Nm |
| Maximum Torque | 102 Nm |
| Continuous Current at Standstill | 14.7 A |
| Maximum Current | 66.2 A |
| Moment of Inertia | 0.0192 kg·m² |
| Protection Class | IP65 |
| Net Weight | 35 kg |
The order-number mapping comes from product listings for R911391203, while the performance figures and frame-level weight are taken from published MSK100B-0200 technical references and distributor technical pages.
Positioning Within Industrial Automation
The MSK100B-0200 is not a small positioning motor for light-duty pick-and-place units. It sits in a class that is more appropriate for machine tools, converting machinery, packaging lines with larger driven sections, rotary indexing systems, and servo-driven production equipment where the motor must manage meaningful inertial loads without losing control quality. Because the motor combines 28 Nm continuous standstill torque with 102 Nm peak torque, it offers both steady-state holding capability and the torque reserve needed for acceleration, deceleration, and intermittent overload events. That operating profile is important in real production environments where the axis rarely runs under ideal steady-state conditions.
From an engineering perspective, the 4100 rpm maximum speed gives the motor useful flexibility. A servo motor in this range can be paired with direct-drive or geared mechanisms depending on the application target. For direct coupling, the motor provides strong controlled torque for precision axes. With suitable transmission design, it can also support higher force output at the machine level. This versatility is one reason motors in the MSK100 class are commonly considered for sophisticated automation systems instead of simple constant-speed drive duties. That conclusion is a practical inference from the published torque, speed, and inertia data.
Mechanical and Thermal Value
Weight is often treated as a minor catalog number, but in practice it matters for transport, mounting, shaft alignment, bracket design, and long-term machine stability. For the MSK100B-0200 platform, the published weight is 34 kg. That is substantial enough to signal a rugged industrial build, yet still within a range that allows practical installation in servo systems without the extreme handling constraints associated with very large spindle or main-drive motors. Buyers preparing spare-parts inventories, export packing, or service replacements should keep this mass in mind for lifting, shipping, and mounting arrangements.
The same logic applies to enclosure protection. Public product references for the MSK100 family show IP65 protection, which is a meaningful specification in industrial settings. It indicates a motor housing suitable for resistance to dust ingress and water jets in typical machinery environments, helping the motor perform reliably where coolant mist, dust, and general industrial contamination are part of normal operation. IP65 does not eliminate the need for correct cable routing, connector sealing, and installation discipline, but it does support deployment in serious factory-duty conditions rather than only in clean laboratory settings.
Application Advantages
| Application Requirement | Benefit of MSK100B-0200-NN-S1-LP0-NSNN |
|---|---|
| High torque demand | 28 Nm continuous torque and 102 Nm peak torque support demanding servo axes |
| Dynamic load changes | High peak torque helps with acceleration and deceleration under varying load |
| Accurate motion control | Synchronous servo architecture supports repeatable closed-loop positioning |
| Industrial environmental resistance | IP65 rating supports deployment in standard factory conditions |
| Mechanical robustness | 34 kg construction indicates a solid frame for larger automation systems |
| System flexibility | 4100 rpm speed allows use in direct-drive or geared machine concepts |
These application benefits are derived directly from the published torque, speed, protection, and weight data, plus standard motion-control engineering interpretation.
Why This Motor Matters for OEMs and Service Teams
For original equipment manufacturers, the value of the MSK100B-0200 lies in predictability. A servo motor chosen for industrial machinery must do more than rotate; it must integrate into a control architecture, maintain consistent response across cycles, and support uptime over long operating periods. The published electrical data for the MSK100B-0200 shows a current and torque profile that fits serious industrial use, not hobby-level motion control. That matters when specifying axes that move tooling, driven rollers, indexing mechanisms, or mechanically resistant process loads.
For maintenance departments and spare-parts buyers, the exact order number R911391203 is equally important. In Rexroth environments, the complete model code is not cosmetic; it determines the actual mechanical and electrical execution delivered to the machine. Using the precise order number together with the full motor designation reduces the risk of ordering a visually similar but functionally different variant. That is especially relevant in older machinery, retrofit work, and international procurement where suffix mismatches can create installation or commissioning problems.
Selection Guidance
When evaluating this motor for a project or replacement job, the correct question is not simply whether the motor is “powerful enough.” The better question is whether its torque-speed behavior, inertia, frame size, protection level, and mechanical execution align with the driven load and the existing Rexroth drive system. The MSK100B-0200 data suggests a motor optimized for substantial industrial servo duty, but exact compatibility still depends on the amplifier, feedback configuration, shaft arrangement, connector orientation, and mounting interface. That is why serious procurement work should always verify the full code rather than relying only on frame size or a partial model reference. This is an engineering recommendation based on the product structure reflected across the listed MSK100B variants and part-number-specific references.
Conclusion
The REXROTH R911391203 MSK100B-0200-NN-S1-LP0-NSNN is a heavy-duty synchronous servo motor built for precise and demanding industrial motion tasks. Its public performance data—4100 rpm maximum speed, 28 Nm continuous standstill torque, 102 Nm maximum torque, 66.2 A maximum current, 0.0192 kg·m² rotor inertia, IP65 protection, and 34 kg weight—shows a motor designed for real machine-duty service rather than light automation. For OEM projects, replacement sourcing, or technical sales documentation, it should be positioned as a robust, high-torque Rexroth servo solution suitable for advanced machinery where precision and load-handling capability must coexist.
